Misa Imaizumi1,2, Waka Ohishi1, Eiji Nakashima3, Nobuko Sera1,4, Kazuo Neriishi5, Michiko Yamada1, Yoshimi Tatsukawa1, Ikuno Takahashi1, Saeko Fujiwara6, Keizo Sugino7, Takao Ando2, Toshiro Usa8, Atsushi Kawakami2, Masazumi Akahoshi1,9, Ayumi Hida1. 1. Department of Clinical Studies, Radiation Effects Research Foundation, Nagasaki 850-0013 and Hiroshima 732-0815, Japan. 2. First Department of Internal Medicine, Graduate School of Biochemical Sciences, Nagasaki University, Nagasaki 852-8501, Japan. 3. Department of Statistics, Radiation Effects Research Foundation, Hiroshima 732-0815, Japan. 4. Department of Metabolism/Diabetes and Clinical Nutrition, Nagasaki University Hospital, Nagasaki 852-8501, Japan. 5. Yachiyo Hospital, Hiroshima 731-0302, Japan. 6. Hiroshima Atomic Bomb Casualty Council, Hiroshima 730-0052, Japan. 7. Nakajima Tsuchiya Clinic, Hiroshima 730-0811, Japan. 8. International Hibakusha Medical Center, Nagasaki University Hospital, Nagasaki 852-8501, Japan. 9. Keiju Hospital, Nagasaki 854-0121, Japan.
Abstract
Context: The risk of thyroid cancer increases and persists for decades among individuals exposed to ionizing radiation in childhood, although the long-term effects of childhood exposure to medium to low doses of radiation on thyroid dysfunction and autoimmune thyroid diseases have remained unclear. Objective: To evaluate radiation dose responses for the prevalence of thyroid dysfunction and autoimmune thyroid disease among atomic bomb survivors exposed in childhood. Design, Setting, and Participants: Hiroshima and Nagasaki atomic bomb survivors who were younger than 10 years old at exposure underwent thyroid examinations at the Radiation Effects Research Foundation between 2007 and 2011, which was 62 to 66 years after the bombing. Data from 2668 participants (mean age, 68.2 years; 1455 women) with known atomic bomb thyroid radiation doses (mean dose, 0.182 Gy; dose range, 0 to 4.040 Gy) were analyzed. Main Outcome and Measures: Dose-response relationships between atomic bomb radiation dose and the prevalence of hypothyroidism, hyperthyroidism (Graves' disease), and positive for antithyroid antibodies. Results: Prevalences were determined for hypothyroidism (129 cases, 7.8%), hyperthyroidism (32 cases of Graves' disease, 1.2%), and positive for antithyroid antibodies (573 cases, 21.5%). None of these was associated with thyroid radiation dose. Neither thyroid antibody-positive nor -negative hypothyroidism was associated with thyroid radiation dose. Additional analyses using alternative definitions of hypothyroidism and hyperthyroidism found that radiation dose responses were not significant. Conclusions: Radiation effects on thyroid dysfunction and autoimmune thyroid diseases were not observed among atomic bomb survivors exposed in childhood, at 62 to 66 years earlier. The cross-sectional design and survival bias were limitations of this study.
Context: The risk of thyroid cancer increases and persists for decades among individuals exposed to ionizing radiation in childhood, although the long-term effects of childhood exposure to medium to low doses of radiation on thyroid dysfunction and autoimmune thyroid diseases have remained unclear. Objective: To evaluate radiation dose responses for the prevalence of thyroid dysfunction and autoimmune thyroid disease among atomic bomb survivors exposed in childhood. Design, Setting, and Participants: Hiroshima and Nagasaki atomic bomb survivors who were younger than 10 years old at exposure underwent thyroid examinations at the Radiation Effects Research Foundation between 2007 and 2011, which was 62 to 66 years after the bombing. Data from 2668 participants (mean age, 68.2 years; 1455 women) with known atomic bomb thyroid radiation doses (mean dose, 0.182 Gy; dose range, 0 to 4.040 Gy) were analyzed. Main Outcome and Measures: Dose-response relationships between atomic bomb radiation dose and the prevalence of hypothyroidism, hyperthyroidism (Graves' disease), and positive for antithyroid antibodies. Results: Prevalences were determined for hypothyroidism (129 cases, 7.8%), hyperthyroidism (32 cases of Graves' disease, 1.2%), and positive for antithyroid antibodies (573 cases, 21.5%). None of these was associated with thyroid radiation dose. Neither thyroid antibody-positive nor -negative hypothyroidism was associated with thyroid radiation dose. Additional analyses using alternative definitions of hypothyroidism and hyperthyroidism found that radiation dose responses were not significant. Conclusions: Radiation effects on thyroid dysfunction and autoimmune thyroid diseases were not observed among atomic bomb survivors exposed in childhood, at 62 to 66 years earlier. The cross-sectional design and survival bias were limitations of this study.
Authors: Peter D Inskip; Lene H S Veiga; Alina V Brenner; Alice J Sigurdson; Evgenia Ostroumova; Eric J Chow; Marilyn Stovall; Susan A Smith; Wendy Leisenring; Leslie L Robison; Gregory T Armstrong; Charles A Sklar; Jay H Lubin Journal: Int J Radiat Oncol Biol Phys Date: 2019-02-12 Impact factor: 7.038
Authors: K E Applegate; W Rühm; A Wojcik; M Bourguignon; A Brenner; K Hamasaki; T Imai; M Imaizumi; T Imaoka; S Kakinuma; T Kamada; N Nishimura; N Okonogi; K Ozasa; C E Rübe; A Sadakane; R Sakata; Y Shimada; K Yoshida; S Bouffler Journal: Radiat Environ Biophys Date: 2020-03-07 Impact factor: 1.925